CVE-2026-96525 in MCP Server Plugin
Summary
by MITRE • 09/26/2026
The MCP Server for WordPress WordPress plugin before 1.8.2 does not perform an ownership or sufficient capability check on its workflow create, update and delete REST routes, allowing users with the Contributor role to modify, delete and create site-wide workflow configuration, including workflows created by administrators.
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Analysis
by VulDB Data Team • 09/26/2026
The vulnerability identified in the MCP Server for WordPress plugin prior to version 1.8.2 represents a critical failure in access control mechanisms within the application's REST API implementation. This flaw specifically affects the endpoints responsible for creating, updating, and deleting workflow configurations. The core technical deficiency lies in the absence of robust ownership verification or sufficient capability checks when processing these requests. In a properly secured WordPress environment, administrative actions such as modifying site-wide configuration settings should be restricted to users with elevated privileges, typically Administrators. However, due to this oversight, the plugin fails to validate whether the authenticated user has the requisite permissions to perform these specific operations on resources they do not own or are not authorized to manage.
This lack of authorization enforcement allows attackers with lower-privilege accounts, such as those assigned the Contributor role, to bypass intended security boundaries. By exploiting this vulnerability, an attacker can interact directly with the REST API endpoints to create new workflow configurations that affect the entire site, modify existing workflows established by administrators, or delete critical operational data. This capability effectively elevates the attacker's privileges from a standard contributor level to one capable of altering fundamental system behaviors and configurations without authorization. The impact is severe because it compromises the integrity of the application's logic layer, allowing unauthorized entities to dictate how automated processes function across the entire WordPress installation.
From an industry standards perspective, this vulnerability aligns with CWE-269, which describes Improper Privilege Assignment, as well as CWE-862, Missing Authorization. The attack vector leverages insecure direct object references or broken access control principles where the system trusts user input regarding resource ownership without server-side validation. In terms of tactical mapping within the MITRE ATT&CK framework for enterprise security, this behavior corresponds to T1078 Valid Accounts and potentially T1496 Local Host Configuration Discovery if used in conjunction with other exploits to map out the environment before making changes. The exploitation does not require complex injection techniques but rather relies on correctly formatted HTTP requests sent by an authenticated user who should logically be restricted from performing these actions.
The operational impact of this vulnerability extends beyond simple data modification. Since workflows often dictate automated processes, email triggers, or content publishing schedules within a WordPress site, unauthorized changes can lead to significant business disruption. An attacker could configure workflows to send sensitive information externally, delete critical automation steps leading to service outages, or create backdoor configurations that persist even after the initial attack vector is mitigated if not properly audited. This undermines the trust model of multi-user environments where different roles are expected to have distinct operational scopes.
To mitigate this vulnerability, organizations must immediately upgrade the MCP Server for WordPress plugin to version 1.8.2 or later, which addresses these authorization checks. For sites that cannot be updated instantly due to compatibility constraints, temporary mitigations should include restricting access to the REST API endpoints associated with workflow management through web application firewall rules if possible. Additionally, implementing strict monitoring and logging of all configuration changes can help detect unauthorized modifications early. It is also advisable to review user roles within WordPress to ensure that no unnecessary contributors have been granted elevated capabilities inadvertently, thereby reducing the attack surface available for exploitation until a permanent patch is applied.